1. Field of the Invention.
This invention relates to safety shields for oil well tools.
2. Description of the Prior Art.
When a well is drilled, there are tools operated within the well to perform many different functions. These include for example, setting and removing plugs and bridges, fracturing, acid treating, cleaning out, cementing, perforating, etc.
Those skilled in the art know that many of these tools have sliding or telescoping members by which certain functions are performed. These functions include opening or closing valves, grasping or releasing fishing necks, setting or releasing slips, etc. Often these telescoping members have external shoulders which come together when the two members are telescoped.
When the tool is on the drilling rig floor, being hoisted and lowered by lines from the derrick, often the bottom of the tool is set down and the members will telescope together. In many cases workmen are positioning a tool to one side of the well and sometimes will carelessly have their hands where the tool telescopes together. Inasmuch as these tools are quite heavy this can result in painful injury or even the loss of fingers.
Specifically, a commonly used tool is a "clean-out tool," a typical example of such tool is shown in my previous patents tabulated below.
U.S. Pat. Nos. 3,406,757, October 22, 1968; 3,446,283, May 27, 1969; 3,651,867, March 28, 1972.
As may be seen, to open the hydrostatic valve of the clean out tool, the two upper members of the tool telescope together, each member has a shoulder which comes together with the other.